Portable slush pit assembly



Oct. 25, 1960 M. A. DANNEHL Erm. 2,957,581`

PORTABLE SLUSH PIT ASSEMBLY Filed Nov. 29, 1957 2 Sheets-Sheet 1 Oct. 25, 1960 M. A, DANNEHL E1- AL 2,957,581

PORTABLE SLUSH PIT ASSEMBLY United States Patent PORTABLE SLUSH PIT ASSEMBLY Melvin A. Dannehl and Cecil K. Jordan, Ponca City,

Filed Nov. 29, 1957, Ser. No. 699,625

9 Claims. (Cl. 210-526) This invention relates generally to improvements in the art of drilling wells by the rotary method, and more particularly, but not by way of limitation, to an improved slush pit assembly particularly adapted for use with seismic drilling units.

As it is well known in the art, seismic surveying is usually performed by detonating a series of explosive charges in relatively shallow bore holes, comm-only known as shot holes, and detecting the resulting reflected and refracted seismic waves at spaced detection points. The number and arrangement of the shot holes will vary with different types of shooting patterns, but the survey of any appreciable area 4requires the drilling of a large number of shot holes. These shot holes are ordinarily formed by use of a light-weight portable drilling unit of the rotary type which can be moved from drilling location-to-drilling location and set up in a minimum of time. At the presen-t time, the drilling mud discharging from the shot hole being formed is directed into a settling basin or slush pit where the cuttings and other foreign matter picked up during the drilling operation will tend ice A further object of this invention is to provide a slusli pit assembly for seismic drilling units which may be eas-1 ily transported from drilling location-,to-drilling location'.

A still further object of this invention is to provide a slush pit assembly for seismic drilling units which may be positioned in direct communication with a shot hole being formed in a minimum of time and with a minimum of labor required. g

Another object of this invention is to provide a slush pit assembly for seismic drilling units, including means for removing cuttings from drill mud in the pit, which is simple in construction, will have a long service life and may be economically manufactured.

Other objects and advantages of the invention will be evident from the following detailed description, when read in conjunction with the accompanying drawings which illustrate our invention.

In the drawings:

Figure 1 is a plan View of a slush pit assembly constructed in accordance with this invention. g

Figure 2 is a vertical sectional view of the slush pit assembly, as `taken substantially along lines 2-2 of Fig. 1.

Referring to the drawings in detail, our novel slush pi-t assembly, generally designated by reference characff ter 4, includes an open-*topped housing 6 having yone end S thereof slanted upwardly and outwardly from theA flat bottom portion 1l) of the housing. The opposite end to settle out of the drilling mud in order that the mud tion of the cuttings and other foreign matter tend to rev main in suspension in the drilling mud and will settle out only if the mud is allowed to stand for an appreciable length of time. Therefore, the drilling mud is normally either recirculated with an appreciable portion of the cuttings and foreign matter suspended in the mud, or an over-supply of mud is used and the slush pit is made of such a size that the drilling mud will remain in the pit for an appreciable length of time before being reused.

The present invention contemplates a novel slush pit assembly which may be easily installed in a position to communicate with the well bore being formed to receive drilling mud discharging from the bore. The assembly receives the discharging used drilling mud and quickly and eliiciently removes the cuttings and other foreign matter from the drilling mud; whereupon the drilling mud may be recirculated through the drill string for a continued drilling operation. Also, the slush pit assembly may be easily loaded onto a truck or the like when the drilling unit is being moved to a new drilling location. All portions of the slush pit assembly are secured in a unitary structure, and the assembly is ready for operation when placed on the ground at a new drilling location.

An important object of this invention is to increase the eiciency of shot hole drilling in seismic surveying operations.

Another object of this invention is to quickly and elliciently remove the cuttings from drilling mud discharging from a shot hole during formation of the hole.

portion of the housing 6 is tapered inwardly and com nected to the opposite sides of a verticallyextending pipe 12. The pipe 12 extends from substantially .the upper edge of the housing 6 to a point below the bottom 1,0 of the housing, as shown in Fig. 2. It will also be obv#n served that the bottom 10 of the housing 6 is cut away to receive the lower portion of the pipe 12 and is suit# ably secured to the pipe, as by welding, to provide iluid tight connection of .the pipe 12 to the housing. A baille 14 is secured lto the upper edge of the housing 6 and the upper end of the pipe 12 to increase the elec-i tive height of the housing 6 around the pipe 12, as will be more fully hereinafter set forth. s

A settling 'basin 16 is supported in the housing 6 adjacent the pipe 12 and has its bottom 18 slanted downwardly and inwardly from the opposite ends of the basin, as it most clearly shown in Fig. 2. One end 19 of the basin 16 is connected to the pipe 12 below the top of the housing 6 and extends around the pipe 12 to the conf nection of the housing 6 to the pipe. It will also be obl served that the pipe 12 is cut away at 20 to receive the bottom 18 of the basin 16 and provide communication between the pipe 12 and the basin 16. The cutavi'ayv portion 20 extends downwardly from the upper end of the pipe 12 to a point substantially below the uppery endl of the pipe for purposes which will be hereinafter set forth.

A trough 22 extends downwardly into the end 8 of the housing 6 into connection with the opposite end 24 of the settling basin 16. The angle of the trough 22 is such that the bottom of the trough provides an extension of the bottom 1S of the settling basin 16, and, in fact, the trough 22 and basin 16 may be formed as a unitary structure and considered as one element. The trough 22 is supported on the end 8 of the housing 6 by suit# able braces 26 and extends outwardly from the housing 6 beyond the end 8. y

A large sprocket 28 is positioned in the center of the housing 6 in a position to extend downwardly into the lowest portion of the settling basin 16. The sprocket 28 is secured on a transversely extending shaft 30 jour'f naled at its opposite' ends in bearings 32 (Fig. l). YThe bearings 32 may be secured on braces 34 extendingjbetween the upper edge of the housing 6 and the upper edge of the settling basin 16 at each side of the assembly.

Another sprocket 36 is secured on a transversely extending shaft 38 at the outer end of the trough 22; The sprocket 36 is substantially smaller than the sprocket 28, for purposes which will be hereinafter set forth. The sprocket shaft 38 is journaled in bearings 40 mounted on braces 42 extending outwardly from the outer end of the trough 22 and is connected at its outer end to a suitable gear box 44. The gear box 44 is operated by a suitable power unit 46 mounted on a bracket 48 on the side of the trough 22. It will be apparent that the power unit 46 may be any desired type of prime mover, such as an electric or hydraulic motor. In any event, the power unit 46 drives the sprocket 36 through the medium ofthe gear box 44 and shaft 38. An endless chain 50 extends around the sprockets 28 and 36, with the lower portion of the chain extending through the trough 22 in the manner shown in Fig. 2. The chain 50 carries a plurality of paddles 52 for conveying cuttings and the like from the settling basin 16 up the trough 22, as will be more fully hereinafter set forth. As shown in Fig. l, the length of each paddle 52 is slightly less than the width of the trough 22 to provide a free movement of the paddles through the trough. It will also be observed that the side walls of the basin 16 are slanted in order that the width of the settling basin 16 is increased from the bottom to the top thereof. Thus, the paddles 52 will effectively move material through the basin only when the paddles are moving along the bottom 18 of the basin. The paddles 52 are secured to the chain 50 in any desired manner, such as by braces 53 as shown in Fig. 2.

We also prefer to use an idler sprocket 54 adjacent the inner end of the trough 22 to retain the paddles 512 against the bottom of the trough. The sprocket 54 is secured on a shaft 56 which is journaled between the adjacent ends of two levers 58. The opposite ends of the levers 58 are pivotally secured by pins 60 to the side walls of the trough 22. A bar 62 extends transversely across the top of the trough 22 above the levers 58 and is anchored at its opposite ends by springs 64 to the sides of the trough, such that the bar 62 is urged toward the trough to contact the levers 58 and in turn urge the idler sprocket 54 toward the bottom of the trough. Thus, the idler sprocket 54 retains the paddles 52 in contact with the bottom of the trough for eiciently scraping cuttings up the trough.

Operation In using the present slush pit assembly, a shallow bore is first dug at the point where the shot hole is to be drilled, with the shallow bore being of a size to receive the lower end portion of the pipe 12. The assembly 4 is then placed on the ground With the bottom of the housing 6 resting on a at portion of the earth, and the lower end of the pipe 12 extending downwardly into the previously dug hole or bore. The portable drilling unit (not shown) is then moved into position and the drill string is moved downwardly through the pipe 12 to drill the shot hole. The pipe 12 is of a size to loosely receive the drill string, whereby the drilling operation may be performed without the drill string contacting the pipe 12 and moving the assembly 4. The drilling operation is performed in the usual manner by rotating the drill string and simultaneously forcing drilling mud downwardly through the drill string. The drilling mud ows upwardly -through the annulus formed between the well bore and the drill string. As the drilling mud discharges from the upper end of the well bore, it flows upwardly into the pipe 12 and then through the cut-away portion 20 of the pipe into the settling basin 16. Normally, the drilling mud will be discharged from the well bore with an apreciable velocity, such that the height of the drilling mud within the pipe 12 will be substantially higher than the 'height of the drilling mud inthe settling basin 16. However, the baffle 14 prevents the drilling mud from spilling over the sides of the housing 6 and facilitates the direction of the drilling mud into the settling basin 16.

When drilling mud is injected into the settling basin 16, the power unit 46 is placed in operation to drive the sprocket 36 in such a direction that the paddles 52 are moved clockwise (when viewed as in Fig. 2) through the settling basin 16 and then up the trough 22. Cuttings and other foreign matter in the drilling mud discharging into the settling basin 16 will tend to settle by gravity and collect in the bottom of the basin. These cuttings will be contacted by the paddles 52 and moved upwardly through the trough 22 for discharge out the outer end of the trough beyond the housing 6. Also, the downward movement of the paddles 52 through drilling mud standing in the settling basin 16, as well as the changes in the direction of flow of the mud through the basin, will tend to settle the cuttings and other foreign matter into the lower portion of the basin where they will be contacted by the paddles and removed through the trough 22.

The drilling mud in the upper portion of the settling basin 16 will be substantially free of cuttings and other foreign matter, and as the level of the drilling mud rises to above the height of the side Walls of the settling basin 16, the drilling mud will overflow into the housing 6. We prefer to form the side walls of the settling basin 16 shorter than the side walls of the housing 6 to facilitate this overflow of drilling mud into the housing 6. A suitable suction hose (not shown) is inserted in the housing 6 and connected to the mud pump of the drilling unit for recirculating the clean drilling mud from the housing 6 ba ck through the drill string.

When the drilling operation is completed and the drilling unit is moved to a new location, the assembly 4 is loaded onto a truck or the like and transported along with the drilling unit. For this purpose, we provide a suitable connector 66 secured on the pipe 12 by use of a rod 68 to facilitate lifting of the assembly 4. The rod 68 is preferably welded to brackets 70, with the brackets 70 being in turn welded to the sides of the pipe 12. The connector 66 may be apertured and pivotally secured on the rod 68 to facilitate engagement of the connector 66 with a wire line extending from the drilling unit or any suitable hoisting apparatus. As the member 66 is pulled upwardly, the housing 6 is tilted toward the slanted end 8 of the housing. When this occurs, any foreign matter which may have been settled out in the housing 6 will be effectively dumped out the slanted end 8 of the housing. The sprockets 28 and 36 and the power unit 46 may be left in their operating positions during lifting and movement of the assembly 4, whereby the assembly 4 will be ready for a subsequent drilling operation at a new location.

From the foregoing it will be apparent that the present invention will materially facilitate the drilling of seismic shot holes. The present slush pit assembly may be placed in communication with the shot hole with a minimum of time and labor involved, and the cuttings and other foreign matter will be efficiently removed from the drilling mud as the drilling mud proceeds through the slush pit assembly. The slush pit assembly will be anchored in operating position in a position where it will not interfere with the drilling operation, yet the assembly may be easily removed for re-installation at a new location. It will be further apparent that the present slush pit assembly is simple in construction, will have a long service life and may be economically manufactured.

Changes may be made in the combination and arrangement of parts or elements as heretofore set forth in the specification and shown in the drawings, it being understood that changes may be made in the precise embodiment shown without departing from the spirit and scope of the invention as defined in the following claims.

We claim:

1. A portable slush pit assembly for receiving the drilling mud from a well bore being drilled by a portable rotary drilling unit, comprising a housing, having an open top and closed bottom and one end thereof slanted upwardly and outwardly, means for tilting said housing toward said slanted end, a trough supporting on the housing, extending downwardly at an acute angle `into the housing and merging into and providing a continuation of the bottom of said housing, the upper end of the trough ybeing positioned outwardly of the respective side of the housing, the inner end portion of said trough being extended upwardly to form an open-topped receptacle within the housing, means for directing drilling mud from the well bore into the inner end portion of the trough, a sprocket rotatably carried by the housing and extending into the receptacle portion of the trough, another sprocket rotatably supported at -the outer end of the trough, an endless chain extending around the sprockets and through the trough, a power unit carried by the housing for turning one of the sprockets, and paddles carried by the chain for conveying drilling mud foreign matter from the receptacle portion of the trough through the outer end of the trough.

2. An assembly as defined in claim 1 characterized further in that the side Walls of the trough, at the receptacle portion of the trough, Iare lower than the side walls of the housing to provide 4an overow of clean drilling mud from the receptacle portion of the trough into the housing.

3. A portable slush pit assembly for receiving the drilling mud from a well bore being drilled by a portable rotary drilling unit, comprising an open-topped settling basin having its bottom tapered downwardly and inwardly from the opposite ends thereof, 'a vertically extending pipe connected to one end of the basin for positioning over the Well bore and directing drilling mud from the well bore into the basin, said pipe being of a size to loosely receive the drill string of the drilling unit, a trough extending upwardly from the opposite end of the basin at an angle to provide a continuation of the slanted bottom of the basin, a sprocket rotatably supported on the basin and extending downwardly into the lower portion of the basin, another sprocket rotatably supported on the end of the trough opposite the basin, an endless chain extending around t-he sprockets and through the trough, means for turning at least one of the sprockets, and a plurality of paddles carried by the chain of a size to convey `drilling mud foreign matter from the basin up 4the trough.

4. An assembly as dened in claim 3 characterized further in including an open-topped housing connected to said pipe and surrounding the basin for receiving drilling mud overowing from the basin.

5. A11 assembly as deflned in claim 4 characterized further in that a baille is provided on the top of said housing adjacent said pipe and is extended around the upper end of said pipe opposite the basin to battle drilling mud into the basin.

6. An assembly as defined in claim 4 characterized further in including a connector secured to said pipe for raising the assembly and the end of the housing opposite the pipe is slanted upwardly and outwardly to drain the housing when the assembly is being raised.

7. An assembly as dened in claim 4 characterized further in that the housing has a at bottom to rest on the ground adjacent the well bore -being drilled, and said pipe extends below the bottom of the housing to engage the ground and anchor the assembly in operating position.

8. An assembly as defined in claim 3 characterized further in including an idler sprocket engaging the chain in the lower end portion of the trough, supports for said idler sprocket, and springs extending from the trough to said supports for urging said idler sprocket toward the bottom of the trough.

9. An assembly as defined in claim 2 in which a spring loaded idler sprocket is rotatably supported within said housing and engages said chain to urge said paddles in cont-act with said bottom of said trough.

References Cited in the tile of this patent UNITED STATES PATENTS 581,036 Pike Apr. 20, 1897 2,196,119 Mitchell Apr. 2, 1940 2,378,798 Schneible June 19, 1945 2,861,688 Harms Nov. 25, 1958 2,865,509 Harlan Dec. 23, 1958 

